The present invention generally relates to a system and method for a vertically integrated construction business and more specifically to a system and method for employing the World Wide Web to vertically integrated the concrete materials procurement, specification, submittals, quotation, testing for compliance with the specifications, automated mixture optimization, and manufacturing processes in the construction industries.
Many items, especially in the construction industry, are actually made up of a complex mixture or compound of different constituent materials. Hence, as each group of the underlying materials themselves vary in physical and chemical attributes, the resulting compounds or materials may become even more complex and varied. Further, some constituent materials, although specified to be the same, may differ substantially in physical and chemical attributes when the constituent material is produced or found at different parts of a country or even the world. Hence, many of these construction materials, when made from similar underlying materials found at different parts of the country, may actually be quite different in physical and chemical specification.
One example of such a complex and varied material is concrete. Concrete may be comprised of many different constituent materials. For example, a typical batch of concrete may include: cement; water to hydrate the cement and make it set or harden; aggregates such as sand, gravel, and rock; and minerals and chemicals which may improve strength and durability or lessen/accelerate the setting time of the concrete. Thus, various types of concrete include fibers embedded in the concrete, flyash, silica fume, slag, and/or other chemicals added to the mixture to give the concrete various physical or chemical qualities. Many of these constituent materials vary across geographic regions. For example, a gravel aggregate quarried in North Carolina may have vastly different properties than a gravel aggregate quarried in Utah. Put another way, nominally the same ASTM Type I cement manufactured by two different vendors may result in entirely different performances in otherwise the same mixtures. Typically, a specification for concrete must take these differences into account.
Additionally, the characteristics of these constituent materials may change as time passes from their production. Hence, many of the constituent materials must be incorporated into a concrete mix within a certain distance from where they are found or produced. Also, the mixed concrete must preferably be used (poured) within a certain distance from the mix plant.
The combined effects of geographic differences in materials and a finite usage area make the concrete industry very regionalized. Specifically, different specifications for the finished concrete will be satisfied using different mix recipes and different constituent materials in different geographic areas.
For example, completed batches of concrete are typically only suppliable within a one hour drive of the construction site. If longer than an hour elapses, the concrete characteristics may change, even slightly. Likewise, although chemical additives and cements are generally suppliable over any distance, aggregates are often suppliable only within about a 20 mile radius of the construction site. Formwork may be suppliable within a 500 mile radius, and trucks and/or finishing equipment may be come from just about anywhere on the same continent as the construction site.
Because concrete (or some other building or construction material) varies so much depending on what specific materials are used to produce the mixture, concrete is generally known by the instructions (called recipes) for mixing the concrete or by the physical and chemical attributes of the resulting concrete. These recipes detail the types, quantities and the specifications (such as ASTM), and sometimes even the geographic location of the aggregate materials that make up the concrete. Each recipe is intended to produce concrete that has certain physical or chemical attributes, such as a certain strength after a certain number of days, a certain curing time, a certain durability, or a certain color. Hence, the concrete may be known as a recipe for mixing, or as a collection of specifications for the final concrete to have.
The concrete specifications or the constituent materials that make up the concrete may be described according to user preferences (e.g., the architect, engineer or contractorxe2x80x94AECxe2x80x94who specifies the concrete), or may be defined by an owner industry standard such as in the case of DOTs (Departments of Transportation). These definitions of concrete are generally either prescriptive (e.g., minimum cement content not less than 500 PCY), performance driven (minimum 28 day strength of 3,000 psi), or a combination of the two. The design and specifications of concrete mixtures used by the construction industry are guided by engineering practice standards and specifications from the U.S. and worldwide professional bodies, and these specifications use standard materials whose specifications are collected in large volumes, with each specific standard being referenced with a unique identification number.
In the United States, the dominant standards organization for concrete engineering and construction is ACI (American Concrete Institute) and ASTM (American Society for Testing and Materials) is dominant for materials testing and specifications. However, even these standards may be tempered by either state or local building codes which may alter these standards because of local conditions, or may provide additional standards to be met. AASHTO (American Association of State Highway and Transportation Officials) and the various Department""s of Transportation (DOTs) standards are dominant for infrastructure (roads and bridges). For heavy structures, such as a dam, the U.S. Bureau of Reclamation or the Army Corps of Engineers may be the governing standards body. In this way, the standards bodies are varied and/or geographically diverse.
As described above, each of these standards organizations may classify and name concrete mixes and constituent materials according to their physical and chemical properties, as well as the type of application. Users may further refine or modify these standards with their own additional or alternate standards. This combination of standard-based and user-defined mixes and materials make the whole universe of concrete specifications and mixture types number in the millions.
Typically, constituent materials are specified in relation to standards. Likewise, concrete batches are generally not specified according to standards (standards organizations don""t specify concrete).
However, the concrete specifications (including a list of individual specification items) may generally be either prescriptive or performance-based. A prescriptive specification item preferably references specific constituent materials and the materials"" attributes and/or constraints while a performance-based specification lists the physical and chemical characteristics of the concrete after production. A concrete recipe or specification may include both prescriptive and performance-based specifications.
Testing on the concrete and the constituent materials is used to both specify materials/mixes and verify compliance with standards and user specifications. Some common tests for concrete properties include strength tests and time-related measurements that provide for a characteristic and a time period in which to measure the characteristic. The strength of the concrete is preferably measured using a block of the concrete in a predefined geometric orientation that is crushed to compression. The block may be performed on 4xc3x978xe2x80x3 or 6xc3x9712xe2x80x3 cylinders, prisms, beams, or cubes. Sample time-related measurements may include the air content, air temperature, concrete temperature, shrinkage, slump, chloride permeability, and unit weight of the concrete. For example, the slump of the concrete is the distance that a standard 12 inch cone of cement will slump down after the mold is pulled off. Slump is a time-variable property.
These tests may be performed on the parent of the test specimen (i.e., the concrete batch from which a specimen was taken), any material within the specimen (e.g., a chemical within the cement), or any composite material that is made out of the material of the specimen (e.g., for a specimen of cement, a batch of concrete made out of the cement).
Because the test results may vary from machine to machine or place to place, the testing machines are preferably also known by a unique name or serial number. These testing machines may include a compression testing machine, Qdrum (heat of hydration), QuadLogger data logging device for recording temperature maturity, air pot, cylinder mold, sieve, or any other type of test equipment. As strength, the heat hydration is an important property of a cementitious mixture and is automatically measured using the Qdrum heat signature calorimeter. The heat signature thus generated enables automatic screening of cement/mineral/chemicals combinations in concrete for quality control, as well as simulation of concrete field performance through materials science modeling.
The different properties of the different concretes may be made part of industry standards. Typically, ASTM, AASHTO, or some other standards body puts bounds on a set of quantifiable materials properties as potentially measured through a set of specified tests. Some examples would be ASTM C150 for Portland cement, ASTM C33 for concrete aggregates, and ASTM C494 for chemicals and mixtures. Unlike mixes, constituent material (e.g., cement) specifiers preferably do not specify the materials specifications. The constituent materials are generally only selected from a list of available standards as permitted in a particular market.
The lab services that test and authenticate the integrity of the materials or the finished concrete are also typically located within a certain distance of the construction site or batch plant. For example, lab services on crushing are preferably located no more than 100 miles form the construction site. Likewise, lab services on mix design are typically located no more than 1000 miles from where the mix was created. The concrete exchange of the present invention typically automatically takes these constraints (or a user""s own geographic constraints) into account, and will not offer solutions that conflicts with these standards.
Likewise, an entity in the concrete or other construction industry often defines its own specifications for materials or finished products. Rather than choosing from the various constraints and materials from the standards organizations, many AEC""s and other entities define tighter constraints which must be met for a specific job.
Preferably, one or more of the objects of the present invention or disadvantages of prior systems are addressed by one or more of the presently described preferred embodiments of the present invention.
An apparatus and method for a vertically integrated construction business. More specifically, an apparatus and method for employing the World Wide Web in a business that vertically integrates the concrete materials procurement, specification, submittals, quotation, testing for compliance with specifications, automated mixture optimization, and manufacturing processes in the construction industries.
In one aspect of the present invention, a relational database is provided with linked data objects that describe physical and chemical quantifiable properties. These quantifiable properties are preferably used to specify test methods which may then be used to create both standards-based and manufacturer-based specifications for concrete constituent materials. These standards-based materials may be used to specify generalized brand named materials.
Concrete recipes utilizing the defined specifications are developed either prescriptively or performance-based. Prescriptive specifications list materials while performance-based specifications are based on material attributes. Concrete recipes comprised of standards-based materials (basemixes) can be instantiated into production mixes using xe2x80x9creal-worldxe2x80x9d local materials. In this way, one generic basemix may be used at different geographic locations to produce actual production mixes.
In one aspect of the present invention, the various batch plants and distribution entities may monitor the concrete mixing process and provide real-time feedback (via XML) to the batch plant as well as to the present system. This feedback may include local environmental conditions or an error in the production batch (which may be communicated to the driver of the concrete truck via cell phone, pager or in-truck global positioning system).
The test methods of the present invention may be used to specify materials and concrete recipes and may also be used in a verification of compliance with standard or manufacture-specified tests. Samples of the concrete or concrete constituent materials may be taken at any location and the results of the tests may be provided to the system entities via XML over the Internet.